On March 6, 2004, a Robinson R22 BETA (registration N7188S) operated by Los Angeles Helicopters was involved in an aviation accident near Long Beach, CA. Investigators recorded the probable cause as: the student pilot's improper use of the cyclic control and the certified flight instructor's inadequate supervision, which resulted in a rollover. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter rolled onto its left side during hover autorotation practice when the student pilot applied improper cyclic input. The instructor's corrective action was insufficient to prevent the main rotor blades from striking the ground.
Accident Description
A helicopter rolled over while a certified flight instructor (CFI) and a student pilot were practicing autorotations from a hover. The aircraft came to rest on its left side after the main rotor blades contacted the ground.
Sequence of Events
On the previous autorotation attempt, the student pilot applied improper left cyclic input. The CFI identified the error to the student and instructed him to try the maneuver again. During the subsequent attempt, the student landed the helicopter and maintained the heading; the CFI did not perceive any lateral movement. However, the CFI then realized that the helicopter was starting to roll to the left. The CFI applied full right cyclic, but the helicopter continued to roll slowly until the main rotor blades struck the ground.
Findings
The CFI stated that the helicopter had no mechanical failures or malfunctions during the flight. The accident was not attributed to any mechanical issue.